Linux Groupware Roundup

Is “organize company to-do list” on your to-do list? Get a jump start on your research into collaboration servers and clients.

For the vast majority of its users, the Internet represents
e-mail and instant messaging. However, even if it
is considered to be a mission-critical service that
should perform at an optimal level, e-mail doesn't
solve every communication problem. Scheduling a meeting with a few
coworkers, for example, can be a tedious task when you don't know the
availability of others or the room where the meeting
might take place.

Groupware is software that
facilitates communication and collaboration through e-mail, calendaring
and scheduling, notes, contacts and task management. Good groupware
solutions offer not only a Web interface for accessibility from
everywhere but also compatibility with native clients on major
platforms such as Linux, Apple Mac OS X and Microsoft Windows.

Usually, the more features a groupware solution offers, the less
scalable it is. Groupware solutions providing many features
generally are suitable for groups composed of no more than a few hundred
users. Those that offer basic groupware functionalities, such as
e-mail, contact and calendaring, are likely to satisfy the requirements
of large deployments, up to thousands of users.

Along with dominant and established products such as Microsoft
Exchange, IBM Lotus Notes and Novell GroupWise, excellent proprietary
and commercial alternatives are available for Linux: Kerio MailServer,
Scalix and Samsung Contact among others. Over the past few years, the
Open Source community also has demonstrated a growing interest in
messaging, calendaring and scheduling solutions. This article focuses
on the status of these open-source efforts. It presents an overview of
the various standards related to groupware software and examines the most
promising projects being developed by the community.

Drafts and Standards

Today, the most supported and implemented standard in calendaring and
scheduling is iCalendar, which defines a common format for
openly exchanging calendaring and scheduling information across the
Internet. Along with iCalendar, two additional standards were proposed,
iCalendar Transport-Independent Interoperability Protocol (iTIP) and
iCalendar Message-Based Interoperability Protocol (iMIP). RFC 3283,
titled “Guide to Internet Calendaring”, summarizes the relationship
between the three standards: “iCalendar is the language used to describe calendar objects. iTIP
describes a way to use the iCalendar language to do scheduling.
iMIP describes how to do iTIP scheduling via e-mail.”

iMIP has seen some success but is not used commonly today. A real-time
Calendar Access Protocol (CAP) also was proposed, but it eventually
expired after only a few implementations of it were put in place.
Because it is universally considered to be not a good concept, CAP is
being abandoned.

Although a trend of using WebDAV to share and edit iCalendar data
emerged from various calendaring software vendors—Apple iCal, Mozilla
Sunbird and Novell Evolution—the Internet Task Force published the
CalDAV specification. The draft proposes a standard to model calendar
events as HTTP resources in iCalendar format. Commitments to
support CalDAV have been made by various open-source groupware
solutions, but the majority of commercial products still has to
adopt the upcoming standard.

More recently, GroupDAV emerged as an effort to create a simple
protocol to connect open-source groupware clients to open-source
groupware servers. More precisely, GroupDAV focuses on three popular
clients: KDE Kontact, Novell Evolution and Mozilla Sunbird. Similar
to CalDAV, the proposed model uses HTTP and WebDAV to store groupware
data, such as events and tasks, using the iCalendar standard, but it
also stores contacts using the vCard standard.

Back Ends/Web Interfaces

E-mail service probably is the most solicited service in any groupware
solution. Most organizations have a solid e-mail system and are
interested in adding groupware-type functionalities on top of the
existing infrastructure. To this end, the development version of Kolab2
makes heavy use of Cyrus IMAP Server's capabilities, including access
control lists, annotations and shared folders. It stores every single
object, such as a contact, event, note or task, in an e-mail message in
the appropriate object's type folder. Kolab2 provides all groupware
features and uses solid open-source server components, including Postfix,
Cyrus IMAP Server, OpenLDAP and ProFTPd.

Kolab2 does not include a Web interface beside its administration
interface, but connectivity is being added to most of Horde's excellent
modules. The Horde Project combines a powerful PHP-based application
framework with modules such as the Webmail program IMP, the calendar
manager Kronolith and the contact manager Turba.

Installing Kolab2 is relatively easy to do, thanks to OpenPKG, a component
that also makes the project deployable on many distributions. Kolab2 does
not support CalDAV nor GroupDAV, and adding support for one of these
protocols is hard, due to the nature of how objects are stored in
Kolab2. In addition, you cannot update a message in IMAP; whenever a modification is
done, identity is lost.

Formerly SKYRiX groupware server, OpenGroupware (OGo) is a feature-full
groupware solution that sits side by side with an existing e-mail
infrastructure. OGo provides group calendars, contacts, tasks,
resources, projects and documents management and a Webmail client. OGo
also provides GroupDAV support. Built on top of the SOPE application
server, OGo has a well-structured architecture. Installation is relatively
easy, as binary packages are offered for most distributions.

Figure 1. OpenGroupware offers calendars, document management and other features
and supports the GroupDAV standard.

Formerly SUSE OpenExchange, OPEN-XCHANGE (OX) provides the same kind of
functionalities that OGo offers, and it also sits on top of an existing e-mail
infrastructure. Built around mainly Java-oriented components, OX
provides a rich Web interface to its groupware features. Although a
little behind other projects with regard to client interoperability, OX
might be a natural choice for those comfortable with Java technologies.

If you don't have a robust e-mail infrastructure
or if you are not particularly tied to it, the
Hula and Citadel Projects are interesting groupware
solutions. The new Hula Server Project, formerly the
proprietary Novell NetMail product, is a complete
mail and calendar server. It provides SMTP, POP3,
IMAP and calendar services as well as a simple and
efficient Web interface. The Hula Server features
CalDAV support, and GroupDAV support is being
added by Martijn van Beers. The installation and
configuration of the Hula Server is easy to do, as
packages are available for many distributions and
the software offers a rich Web interface for managing
all components of the system.

Figure 2. Hula, once Novell NetMail, has a simple,
efficient Web interface. The Hula Address Book is
shown here.

Citadel is a multithreaded groupware server implementing all mail
standard protocols, although it can integrate with an existing mail
transfer agent. Standard groupware functionalities such as mail,
calendar, contacts, notes and tasks are supported. It offers a Web
interface through WebCit in addition to a text interface. Citadel also
joined the GroupDAV effort and already provides a working
implementation.

Moving to a different sector, universities aggressively are integrating
portal engines in their infrastructures, especially uPortal. Offering
groupware functionalities in the portal is appealing. Projects such
as University of British Columbia (UBC) Webmail and UBC Address Book
have matured and are well integrated in uPortal. For calendaring
services, the University of Washington (UW) Calendar Project can be
integrated as a portlet in the portal engine, although the support is
preliminary. Support for native clients, such as Novell Evolution or
MeetingMaker, also is planned.

Additional projects are worth mentioning but should still be
considered experimental: exchange4linux, OpenOffice.org Groupware and
its Glow client and Chandler. Well funded by the Mellon Foundation,
Chandler eventually could become a key player. Development activity also is
dissipated among a cluster of overlapping projects based on PHP,
such as eGroupWare, phpGroupWare and more.groupware. Despite their
impressive number of features, these projects lack maturity and cannot
be scaled for enterprise-wide deployments. In addition, most of them
don't support clients other than a Web browser.

Table 1 presents the groupware servers described above and lists their
respective functionalities. Some of those functionalities
currently are in development.

Yeah i don't think there is much of an improvement over OSX in Hula. Some small things, but really not much. For me, it doesn't bring anything new on the table. (but that my opinion, some may have improvements they like).
Matt, ramen chef.

Well, this article is pretty dubios, isn't it? OSX server already includes 95% of what Hula has and then Hula just provides some half-working web interface and has no properly working IMAP4 support. Don't even ask for Outlook support.

I'll bet OSX server is going to include SOGo: integrates nicely with Cyrus and OpenDirectory (aka the existing infrastructure) and is written in the systems language, ObjC.